Makita 3709 Trimmer

Product Specifications

Specifications are subject to change without notice and may differ by country.

General Power Tool Safety Warnings

WARNING: Read all safety warnings and all instructions. Failure to follow the warnings and instructions may result in electric shock, fire and/or serious injury.

Save all warnings and instructions for future reference.

The term "power tool" refers to mains-operated or battery-operated tools.

Work Area Safety

• Keep work area clean and well lit. Cluttered or dark areas invite accidents.
• Do not operate power tools in explosive atmospheres (e.g., presence of flammable liquids, gases, or dust) as they create sparks.
• Keep children and bystanders away to maintain focus and control.

Electrical Safety

• Ensure power tool plugs match the outlet. Never modify plugs or use adapter plugs with earthed tools.
• Avoid body contact with earthed surfaces (pipes, radiators, etc.) to reduce electric shock risk.
• Do not expose power tools to rain or wet conditions.
• Do not abuse the cord: never use it for carrying, pulling, or unplugging. Keep it away from heat, oil, sharp edges, and moving parts.
• Use outdoor-suitable extension cords for outdoor use.
• Use a Ground Fault Circuit Interrupter (GFCI) for damp locations.

Personal Safety

• Stay alert, use common sense, and do not operate while tired or under the influence of drugs, alcohol, or medication.
• Always wear eye protection. Use other protective equipment like dust masks, safety shoes, or hard hats as appropriate.
• Prevent unintentional starting: ensure the switch is OFF before connecting to power or battery, picking up, or carrying the tool.
• Remove any adjusting key or wrench before turning the tool on.
• Maintain proper footing and balance to ensure better control.
• Do not wear loose clothing or jewelry. Keep hair, clothing, and gloves away from moving parts.
• Ensure dust extraction and collection facilities are connected and used properly.

Power Tool Use and Care

• Do not force the power tool; use the correct tool for the application.
• Do not use the tool if the switch does not operate correctly; it must be repaired.
• Disconnect the tool from the power source before making adjustments, changing accessories, or storing it.
• Store idle tools out of reach of children and ensure only trained persons operate them.
• Maintain tools: check for misalignment, binding, or broken parts. Have damaged tools repaired before use.
• Keep cutting tools sharp and clean for easier control and to prevent binding.
• Use the tool, accessories, and bits according to instructions, considering working conditions.

Service

• Have repairs performed by qualified personnel using identical replacement parts.
• Follow instructions for lubricating and changing accessories.
• Keep handles dry, clean, and free from oil and grease.

Extension Cord Use: Use a good condition, sufficiently heavy extension cord. An undersized cord causes voltage drop, power loss, and overheating. Refer to Table 1 for correct gauge based on cord length and amperage.

Trimmer Safety Warnings

• Hold the tool by insulated gripping surfaces to prevent the cutter from contacting its own cord.
• Use clamps or other practical means to secure the workpiece to a stable platform.
• Wear hearing protection for extended operation.
• Handle bits carefully.
• Inspect bits for cracks or damage before use. Replace immediately if damaged.
• Avoid cutting nails; inspect and remove all nails from the workpiece before operation.
• Hold the tool firmly.
• Keep hands away from rotating parts.
• Ensure the bit is not contacting the workpiece before switching the tool on.

Operation

Place the tool base on the workpiece without the bit touching it. Turn the tool on and wait for the bit to reach full speed. Move the tool forward over the workpiece surface, keeping the base flush and advancing smoothly. For edge cutting, the workpiece surface should be on the left side of the bit in the feed direction.

Note on Feed Rate: Moving too fast can result in poor cut quality or damage. Moving too slowly can burn the workpiece. Adjust feed rate based on bit size, workpiece type, and cut depth. Perform a test cut on scrap lumber first.

Templet Guide: This guide has a sleeve for the bit, allowing use with templet patterns. Remove the chip deflector. Loosen base protector screws, place templet guide on base, reattach protector, and tighten screws. Secure the templet to the workpiece and slide the tool along the templet guide.

Straight Guide (Optional Accessory): Useful for straight cuts, chamfering, or grooving. Attach the guide plate to the straight guide with the bolt and wing nut. Attach the straight guide to the tool with the clamp screw (A). Adjust the distance between the bit and guide using the wing nut. For cuts where the workpiece side is too far or not straight, clamp a straight board to the workpiece and use it as a guide against the trimmer base.

Circular Work: Assemble the straight guide and guide plate as shown. Minimum radius: 70 mm (2-3/4"). Maximum radius: 221 mm (8-11/16"). For circles between 70 mm (2-3/4") and 121 mm (4-3/4"), use the guide. For circles between 121 mm (4-3/4") and 221 mm (8-11/16"), use the guide. Circles between 172 mm (6-3/4") and 186 mm (7-5/16") cannot be cut with this guide. Align the center hole of the straight guide with the circle's center, insert a nail to secure it, and pivot the tool clockwise.

Functional Description

Adjusting Bit Protrusion

The tool base can be moved up or down by turning the adjusting screw. Loosen the clamping nut, adjust, then tighten the nut securely.

Switch Action

Move the switch lever to I (ON) to start, and to O (OFF) to stop. Always ensure the tool is switched OFF before plugging it in.

Assembly

Installing or Removing Trimmer Bit

Do not tighten the collet nut without a bit inserted, as it can break the collet cone. Use only provided wrenches. Insert the bit fully into the collet cone and tighten securely. Reverse the process to remove.

Maintenance

CAUTION: Always ensure the tool is switched OFF and unplugged before performing inspection or maintenance.

Never use gasoline, benzine, thinner, alcohol, or similar products, as they can cause discoloration, deformation, or cracks.

Replacing Carbon Brushes

Regularly inspect and replace carbon brushes when worn down to the limit mark. Keep brushes clean and ensure they slip freely. Replace both brushes simultaneously. Use only identical Makita carbon brushes. Use a screwdriver to remove brush holder caps, replace worn brushes, and secure the caps.

Optional Accessories

The following accessories are recommended for use with this tool. Using other accessories may pose a risk of injury. Consult your local Makita Service Center for details.

• Straight & groove forming bits
• Edge forming bits
• Laminate trimming bits
• Straight guide assembly
• Trimmer guide assembly
• Trimmer base assembly (for chamfering with straight bit)
• Trimmer shoe
• Templet guide
• Collet cone 1/4"
• Wrench 10
• Wrench 17

Note: Some items may be included as standard accessories and may vary by country.

Makita Limited One Year Warranty

Makita tools are inspected and tested before leaving the factory. They are warranted to be free of defects in workmanship and materials for ONE YEAR from the original purchase date. Return the complete tool, freight prepaid, to a Makita Factory or Authorized Service Center for repair or replacement if a defect is found. This warranty does not apply if repairs were attempted by others, if the tool is worn, abused, misused, improperly maintained, or altered.

Makita is not liable for indirect, incidental, or consequential damages. Makita disclaims implied warranties of merchantability and fitness for a particular purpose after the one-year term.

This warranty provides specific legal rights, and other rights may vary by state.

California Proposition 65 Warning

WARNING: Some dust created by power sanding, sawing, grinding, drilling, and other construction activities contains chemicals known to the State of California to cause cancer, birth defects or other reproductive harm. Examples include lead from lead-based paints, crystalline silica from bricks and cement, and arsenic and chromium from chemically-treated lumber. To reduce exposure, work in a well-ventilated area and use approved safety equipment, such as dust masks designed to filter microscopic particles.